Description: A considerable amount of Haas' research from the 1950s onwards involved identifying language family relationships and constructing proto-languages. Comparisons, both lexical and phonological, between Algonquian languages and what Haas labeled ‘Proto-Algonkian, ‘Proto-Central Algonkian and ‘Proto-Central-Eastern Algonkian' (often abbreviated to PA, PCA and PCEA respectively) are abundant especially throughout Series 2 and Series 9. Haas made annotations to others' publications, created bibliographies, and developed family trees and lexica of both Proto-Algonquian and a wide variety of Algonquian languages, including several lexica from multiple historical sources in Series 9. Examples of the above are to be found across much of the collection, often in folders of specific Algonquian languages. See individual cultures and languages for specifics.